The invention relates to a thermal switch arrangement for electromagnetic coils, particularly of electric motors.
In many cases, electromagnetic coils are protected against excessive temperatures in the winding with the help of a thermal switch, which is also referred to as a "safety temperature limiter". Excessive temperature in the winding of the coil former, which takes up the winding, or perhaps of a motor in its totality, could lead to damage or destruction of the motor or its parts. Moreover, overheating the motor also implies the danger of a fire. For this reason, the thermal switches are disposed and connected at or on the coil in such a manner, that they interrupt the current in the winding when a specified temperature is exceeded.
Usually, the thermal switches are connected in series with the windings. This can be accomplished, for example, owing to the fact that the thermal switch is soldered with one of its tags to a flat plug of the winding, which is fastened to the coil former, while the other end of the winding wire is soldered to the other tag of the thermal switch. The production of the two soldered sites represents a timeconsuming interruption of the installation of the coil, which not only delays the production, but also makes it more expensive. If soldering is carried out in the immediate vicinity of the coil, it is also possible for the soldering tin to reach the surface of the winding, damaging it. In particular, the insulation of the individual copper wires, generally enameled copper wire, may be damaged.